What Burton Richardson is doing, Redzone, STAB, what's taught at Impact, Richard Dimitri, what this guy I trained with named Mark Worland teaches, Eric Cobb, What Dog Brother Michael Pinafiel & I have taught together in seminars, etc have a huge COMMONALITY of technique.
[If you can't run away or get cover, a weapon etc...] BASICALLY get a 2-on-1 on the weapon bearing limb, then you can do different stuff from there.
Some teach very specific controls (e.g. baseball bat grip on the wrist or a more classic inside or outside 2-on-1) some just say control the limb in any way you can.
But the REAL learning comes from the scenario drills/ sparring. That's where you learn. There's not very much technique; it's simple but not easy. It's about learning the principles and getting good at appling them.
Grapplers/BJJ players are especially suited to this kind of training because they understand what it means to really hold onto a limb, they understand physical closeness and they have the kind of proprioception, understanding of base, etc that is really useful.
This is what BJJ schools should be teaching. Not some moves copied out of a book 85 years ago.